1. Field of the Invention
The present invention relates to an optical pickup for use in a disk player such as a CD player or a DVD player, and more particularly to an optical pickup in which a photodiode can be positioned precisely.
2. Description of the Related Art
JP-A-2001-67710 discloses conventional techniques regarding optical pickups. JP-A-2001-67710 discloses an optical pickup in which an objective lens is disposed at one end opening of a light passage hole with a half mirror. The light passage hole is provided penetratingly in a synthetic resin-made base. A laser diode is disposed in a laser hole communicating with the light passage hole. A mounting surface is formed on the other end opening of the light passage hole. A resilient plate is secured to the mounting surface by a screw. The resilient plate has on one end thereof an opening on which a photodiode is disposed, and has on the other end thereof a screw hole through which the screw is inserted. The photodiode is positioned in X-Y-Z directions by adjusting the screwing amount of the screw.
In the above-described construction, since an interval between the screw, which is a reference for fixing the resilient plate, and the photodiode is large, as the base is thermally expanded by the heat generated by the laser diode, the optical axis of the laser light is likely to be offset from the central axis of the photodiode in the horizontal longitudinal direction. Consequently, an error can possibly occur in the reading by the photodiode.